ON THE AGROFORESTRY SYSTEM AND IN SITU CONSERVATION OF MEDICINAL GERMPLASM IN TRANS- NZOIA DISTRICT, KENYA

J. M. Ochora 1, J. M. Onguso2 and J. I. Kany 3 1,3Department of Botany, Jomo Kenyatta University of Agriculture and Technology, Nairobi 2 Institute of Biotechnology Research, Jomo Kenyatta University of Agriculture and Technology, Nairobi E-mail: [email protected]

Abstract In sub-Saharan Africa about 80% of the ever increasing population depends on ethnomedicine for their healthcare since modern medicine is mostly expensive or unavailable in rural homesteads. However, ethnomedicine is the one presently recognised as the most effective in treating new emerging diseases such as HIV/AIDS since no effective conventional medicine exists for their cure. Medicinal germplasm, which are the major sources of ethnomedicine form an important part of forests and riverine vegetation in Kenya. These important plants include Warburgia, Rhas spp., Aspilia, Acacia, prunus, Molinga, Brascae, Aloe, and Terminalia. These plants are not only useful to man as a source of medicine but are microhabitats for many animals as well as forming “refugia” to many insects species. In Kenya, due to land degradation and rampant deforestation in agriculturally high potential areas, medicinal plants genetic resource is threatened. The most medicinally popular of these plant species, which are mostly biome restricted, are facing extermination. This paper reports conservation concerns in agriculturally high potential Trans-Nzoia District in Kenya. The study based on field surveys revealed that of the ca. 806 plants species in 92 families about 36 species are used for medicinal purposes. The plants are threatened in their indigenous localities in the District. The study recommends participatory in situ plant conservation in the District along maize and wheat farm hedges.

Key words: Agroforestry, in situ conservation, medicinal plants, indigenous medicines

120 1.0 Introduction As the demand for arable land and urban settlement increases in Kenya, more of the existing forest land is being excised for use as farmlands and urban infrastructural expansion. These activities have led to clearing of important forests and game reserves. The forest depletion seems to relate very well with population pressure backed by the fact that the backbone of Kenya’s economy is agriculture.

Although surveys to map the proportion of plant species that are lost each year have not been comprehensively carried out, it is not surprising to discover that an overwhelming number of plants especially those of medicinal importance is eroded.

As previously established, Kenya has a rich plant heritage with the most potent biochemicals (Kokwaro, 1983; Riley and Brokensha, 1988). Even if only a few medicinal plants have been documented for deforested areas of Kenya (Kanya 2004; Ochora et al., 2005) it is envisaged that many more destroyed plants fall under this category. Ex situ conservation strategies especially in garden environment (Frankel et al., 1995) are not suitable for trees and also for large populations of herbs, scrubs or shrub species.

2.0 Methods 2.1 Establishment of the Baseline and Number of Sampling (Transect Lines)

The transect intercept method (Grieg-Smith, 1983)of sampling was employed. At each sampling site, a 1 km baseline with a west-east orientation was established. These points were randomly placed along this baseline through which a sampling line (transect) passed. Three transect lines (each 50 m) were established which intersected the baseline at midpoints (William, 1986). The orientation for each transect was randomized by selecting a number between 0o and 360o.

2.2 Measurement on Each Baseline As each line was traversed, the plants species intercepted by the transect line were identified to produce a species list (Agnew, 1994; Beetle, 1994). Where field identification of species was not possible in the field, voucher specimens were collected for later identification at the East African Herbarium (EA).

The field work was done for a period of one year during cropping and non-cropping seasons. In each sampling site in the farms a baseline, 1 Km. long, was established orientating in a west-east direction. Three random points were located along the baseline through which sampling line (transect) passed. Transect lines were used such that as the line was traversed the plant species intercepted by the transect line were identified to produce a species checklist. The recorded plants were compared with the vegetation lists for Mt. Elgon forest available at the East African Herbarium. This montane vegetation is the remnant of indigenous plants of the District.

3.0 Results A checklist of plants ca. 806 in 92 families was established (Table 1). Except for plants in the categories of herbs and scrubs that easily rejuvenate from propagules in the farmlands, most shrubs and trees earlier recorded for Trans-Nzoia District are of rare occurrence. Conspicuously absent were the highly medicinal plants such as Warburgia, Prunus, Carissa, and Rhas (Table 2) that were once dominant in the region.

121 Table 1: A checklist of plant species recorded in Trans-Nzoia District during cropping and non-cropping seasons

Family Plant Species Family Plant Species Acanthaceae Acanthus pubescens Amaranthaceae Achylanthes aspera Asystasia mysorensis Amaranthus caudatus Asystasia schimperi Amaranthus graecizana Barleria micrantha Amaranthus hybridus Dyschoriste radicans Celosia trigyna Hygrophila auriculata Cyathula polycephala Hypoestes forskahlii Justicia exigua Amaryllidaceae Scadoxus multiflorus Justicia flava Justicia striata Anacanthaceae Rhus natalensis Justicia whytei Rhus vulgaria Monechma debile Ruellia patula Anacardiaceae Lannea edulis Thunbergia elliotii Mangifera indica Thunbergia gregorii Ozoroa insignis Tithonia aethiopica Agave sisalan Annonaceae Annona squamosa

Anthericaceae Chlorophytum gallabatense Apiceae Sanicula elata

Apocynaceae Carissa edulis Araceae Arisaema enneaphyllum Landolphia buchananii

Araliaceae Cussonia holstii Aslepiadiaceae Periploca linearifolia Striga hermonthica Asphodelaceae Bulbinella abyssinica Asteraceae Acanthospermum autriale Bignoniaceae Jacaranda mimosifolia Acanthospermum glabratum Markhamia lutea Acanthospermum hispidium Spathodea campanulata Acmella calirhiza Ageratina adenophora Boraginaceae Cordia Africana Ageratum conyzoides Cynoglosum coeruleum Ageratum houstoniamum Cynoglossum geometricum Anthemis tigreensis Cynoglosum lanceolatum Artemisia afra Ehretia cymosa Aspilia pluriseta Trifolium burchellianum Bidens pilosa Blumea aurita Brassicaceae Crambe kilimandscharica Balumea scaposa Raphanus sativus Bothriocline tomentosa Bromeliaceae Ananas comosus Centaurea mollis Cirsium buchwaldii Buddlejaceae Buddleja madagascariensis Conyza aegyptiaca Buddleja polystachya Conyza schimperi Conyza stricta Burseraceae Commiphora Africana Conyza sumatrensis Conyza volkensii Caesalpiniaceae Chamaecrista hildebranditii Crassocephalum afromontana Chamaecrista mimosoides Crassocephalum mannii

122 Piliostigma thonningii Crassocephalum montuosum Senna didymobotrya Crassocephalum picridifolium Senna singueana Crassocephalum vitellium Canjanus cajan Crepis carbonaria Dichrocephala integrifolia Capparaceae Cleome monophylla Emilia discrifolia Gynandropsis gynandra Euryops brownie Galinsoga alba Caricacea Carica papaya Galinsoga parviflora Gamolepis chrysanthemoifes Caryophyllaceae Cerastium indicum Gerbera viridifolia Cerastium octandrum Gnaphalium luteo-album Drymaria cordata Gnaphalium rubriflorum Silene burchellii Guizotia scabra Silene gallica Gutenbergia bonariensis Basella alba Gutenbergia cordofolia Helianthus annua Casuarinaceae Cassuarina cannighamii Helichrysum cymosum Helichrysum cymosum Calastraceae Maytenus heterophyla Helichrysum formosissimum Maytenus senegalensis Helichrysum gerberifolium Helichrysum odoratissimum Chenopodiaceae Chenopodium opulifolium Helchrysum setosa Chenopodium procerum Inula decipiens Lactuca capensis Compretaceae Compretum collinum Lagascea alata Compretum molle Lagascea mollis Laggera brevipes Commelinaceae Anailema johnsonii Launaea cornuta Commelina Africana Melanthera scandens Commelina benghalensis Microglossa pyrifolia Commelina repens Pycreus lanceolatus Schkuhria pinnata Convolvulaceae Convolvulus kilimandschari Sigesbeckia abyssinica Convolvulus mombasana Solanecio angulatus Dichondra repenes Sonchus asper Evolvulus alsinoides Sonchus oleraceus Falkia canescens Sporobolus Africana Ipomoea batatas Teclea nobilis Ipomoea kituiensis Tithonia diversifolia Ipomoea obscura Toddalia asiatica Ipomoea purpurea Vernonia auriculifera Vernonia brachytrichoides Crassulaceae Bryophylum pinnatum Vernonia galamensis Kalanchoe densiflora Vernonia hymenolepis Kalanchoe lanceolata Vernonia karaguensis Kalanchoe mitejea Vernonia lasiopus Vicia faba

Cruciferae Brassica integrifolia Cupressaceae Cupressus lustanica

123 Brassica juncea Brassica nupus Cyperaceae Bothrichloa inscupta Brassica oleraceae Carex monostachya Erucastrum arabicum Cyperus alba Lepidium bonariense Cyperus assimilis Cyperus bulbosa Coccinia grandis Cyperus dichrostachyus Cucumis aculeatus Cyperus distans pepo Cyperusgiolii abyssinica Cyperus hemisphaericus Lagenaria sphaerica Cyperus immensis Mormodica calantha Cyperus involucratus Mormodica foetida Cyperus kilimandschari Mormodica friesiorum Cyperus latifolius Mukia maderaspantana Cyperus macrocephala Peponium pepo Cyperus niveus Peponium volgellii Cyperus obusiflorust Zornia glochidiata Cyperus rigidifolius Cyperus rohlfsii Dennstaedtiacaea Hypolepis goetzei Cyperus rotudus Pteridium aquilinum Cyperus sieberiana Cyperus tenuifolia Dioscoreaceae Dioscorae schimperiana Cyperus tomaiophyllus Diospyros abyssinica Fimbristylis subaphylla Euclea divonorum Fuirena leptostachya Mariscus macrocarpa Epacridaceae Richea albeltii Schoenoplectus corymbosus Schoenoplectus senegalensis Euphobiaceae Acaclypha volkensii Scleria racemosa Clutia abyssinica Clusia robusta Flacourtiaceae Dovyalis caffra Manhot esculenta Dovyalis macrocalyx Phyllanthus fischeri Oncoba spinosa Ricinus communis Triticum aestivum Tribulus terrestris Acalypha volkensii Gentianaceae Syzygium cordatum Croton macrostachyus Croton megalocarpus Geraniaceae Geranium arabicum Erythrococca bongensis Pelargonium quinquelobatum Euphorbia crotonoides Euphorbia hirta Guttiferae Hypericum peplidifolium Euphorbia inaequilatera Euphorbia prostrate Iridaceae Gladiolus psittacinus Euphorbia ugandensis Gladiolus ukambanensis Phyllantus spp. Flueggea virosa Labiatae Achyrospermum schimperi Sapium ellipticum Ajuga remota Fuerstia Africana Lauraceae Persea Americana Hoslundica opposite Lantana camara

124 Liliaceae Gloriosa surperba Leonotis mollissima Ornithogalum tenuifolium Leonotis nepetifolia Aloe lateritia Leucas calostachys Asparagus africanus Leucas deflexa Leucas glandis Loranthaceae Phragamanthera usuiensis Leucas martinicensis Leucas mollis Malvaceae Abutilon longicuspe Leucas neuflizeana Abutilon mauritianum Ocimum gratissimum Hibiscus calyphyllus Ocimum kenyense Hibiscus cannabinus Ocimum kilimandscharicum Hibiscus diversifolius Ocimum lamiifolium Hibiscus fuscus Plectranthus barbatus Hibiscus greenwayi Plectranthus edulis Hibiscus rhomboidea Plectranthus laxiflorus Hibiscus trionum Hibiscus vitifolius Plectranthus parvus Kosteletzkya adoensis Pycnostachys stuhlmannii Malva verticillata Salvia merjamie Pavonia patens Salvia microphylla Pavonia urens Satureia biflora Sida acuta Stephanie abyssinica Sida Africana Sida cordifolia Melastomataceae Dissotis brazzae Sida rhombifolia Sida tenuicarpa Melastomaceae Dissotis brazzae Sida ternata

Meliaceae Ekebergia capensis Meliaceae Ekebergia capensis

Melianthaceae Bersama abyssinica Menispermaceae Cissampelos mucronata Mimosaceae Acacia albida Musaceae Enzete ventricosa Acacia gerrardii Musa parasidiaca Acacia hockii Musa sapiens Acacia lahai Acacia meansii Myrsinaceae Embelia schimperi Acacia nilotica Maesa lanceolata Acacia sieberina Calliandra caly Myrtaceae Eucalyptus camaldulensis Entada abyssinica Eucalyptus saligna Albizia gumifera Psiadia guajava Syzygium guineensis Tegetes minuta

Nyctaginaceae Bougaivillea spectabilis Oleaceae Fraxinus pennsylvanica Jasminum fluminense Olea capensis Schrebera alata Onagraceae Jussiaea abyssinica Ludwigia abyssinica Oxalidaceae Oxalis corniculata Oxalis

125 latifolia Oxalis obliquifolia Palmae Phoenix reclinata Passifloraceae Passiflora edulis Papilionaceae Alysicarpus glumaceus Antopetitiana abyssinica Pedaliaceae Sesamum angolensis Astragalus atropilosulus Sesamum calycimum Caesalpinia decapetala Cassia mimosoides Phytolaceae Phytolacca dodecandra Cassia obtusifolia Crotalaria brevidens Plantaginaceae Plantago lanceolata Crotalaria hyssopifolia Plantago palmate Crotalaria incana Crotalaria incanum Crotalaria recta Poaceae Sorgum vulgare Crotalaria spinosa Andropogon abyssinicus Desmodium adscendens Aristida adoensis Desmodium intortum Beckeropsis uniseta Desmodium repandum Bothriochloa inscupta Desmodium uncintortum Bothriocline longipes Dichrostachys cinerea Brachiaria brizantha Eriosema macrostipulum Brachiaria decumbens Eriosema pauciflorum Chloris gayana Erythrina abyssinica Chloris pycnothrix Glycine whytei Cymbopogon caesius Indigofera arrecta Cymbopogon diplandra Indigofera fischeri Cymbopogon dissolute Indigofera mimosoides Cymbopogon nardus Indigofera nairobiensis Cynodon dactylon Indigofera spicata Dactyloctenium aegyptium Indigofera volkensii Digitaria scalarum Leucaena glauca Digitaria ternate Phaseolus vulgaris Digitaria velutina Pisum sativum Echinochloa pyramidalis Pseudarthria hookeri Echinochloa haploclada Pterolobium stellatum Eleusine coracana Rhynchosia elegans Eleusine glaucum Rhynchosia kilimandscharica Eleusine indica Rhynchosia minima Eleusine jaegeri Rhynchosia parkeri Eragrostis aspera Sesbania sesban Eragrostis brownie Tephrosia holstii Eragrostis ciliaris Thalictrum rhyncocarpum Eragrostis exasperate Trifolium usambarensis Eragrostis humidicola Trimeria grandifolia Eragrostis pellucidus Typha domingensis Eragrostis rigidifolius Vigna monophyla Eragrostis tenuifolia Vigna parkeri Floscopa glomerata Viola abyssinica Harpachne schimperi Zornia setosa Hyparrhenia collina

126 Hyparrhenia cymbarica Polygalaceae Polygala sphenoptera Hyparrhenia filipendura Fallopia convolvus Hyparrhenia hirta Oxygonum sinuatum Hyparrhenia rufa Polygonum nakuruense Hyperthelia dissolute Polygonum nepalense Imperata cylindrical Polygonum pulchrum Leersia hexandra Polygonum salicifolium Loudetia kagerensis Polygonum senegalensis Microchloa kunthii Rumex abyssinica Oplismenus hirtellus Rumex bequaertii Panicum deustum Panicum maximum Portulaceae Portulaca oleraceae Panicum pyramidalis Portulaca quadrifida Paspalum auriculatum Paspalum commersoni Proteaceae Grevillea robusta Paspalum scrobiculatum Pennisetum cladestinum Ranunculaceae Clematis brachiata Pennisetum giganteum Ranunculus multifidus Pennisetum polystachya Thea sinensis Pennisetum purpureum Pennisetum squamulatum Resedaceae Caylusea abyssinica Pennisetum trachyphyllum Rhynchelytrum repens Rhamnaceae Gouania longispiculata Saccharum officinarum Helinus mystacinus Setaria plicatilis Scutia myrtina Setaria pumila Setaria sphacelata Rosaceae Alchemilla johnstonii Setaria verticilata Alchemilla kiwuensis Sorghastrum rigidifolium Eriobotrya japonica Sorghastrum stiopoides Prunus Africana Sorghum arundinaceum Rubus pinnatus Sporobolus pellucidus Rubus scheffleri Sporobulus pyramidalis Rubus steudneri Stachys aculeolata Thunbergia alata Arabica Triumfetta annua Galium spurium Zehneria scabra Kohautia coccinia Zea mays Oldenlandia herbacea Pentanicia ouranogyne Rutaceae Citrus limon Pentas longiflora Tephrosia hildebrandtii Richardia brasiliensis Torilis arvensis cordifolia Spermacoce princeae Solanaceae Datura metel Sphaeranthus bullatus Datura stramonium Vangueria madagascariensis Lycoperscon esculentum Verbena bonariensis Nicandra physalodes Physalis peruviana Sterculiaceae Dombeya burgessiae Solanum aculeastrum Dombeya torrida Solanum anguivi

127 Solanum incanum Theaceae Camelia sinensis Solanum nigrum Themeda triandra Solanum schumannianum Solanum teberosum

Tiliaceae Corchorus trilocularis Typhaceae Typha domingensis Grewia bicolor Grewia similis Ulmaceae Celtis africana Spermannia ricinocarpa Triumfetta macrophylla Umbelliferae Agrocharis incognita Triumfetta rhomboidea Apium leptophylum Tylosema fassoglensis Centella asiatica Erythroselinum atropurpareum Verbenaceae Clerodendrum myricoides Hydrocotyle ranunculoides Clerodendrum rotundifolium Oreoschimperella aberdarensis Lippia javanica Priva curtisiae Tragia brevipes Verbena brasiliensis Vernonia amygdalina Cissus oliveri Cyphostemma kilimandschari Cyphostemma serpens Rhoicissus tridentate

Urticaceae Girardinia diversifolius Zygophyllaceae Trichodesma zeylanicum Laportea alatipes Pouzolzia parasitica Urtica massaica Vangueria infuasta

Table 2: Some medicinal plants of Trans-Nzoia District

Botanical name (Family) and part(s) used 1. Acacia spp. (Fabaceae): Bark 2. Aloe spp. (Aloeceae): and tuberous 3. Asparagus Africana (Asparagaceae): Tuberous roots 4. Balanites glabra (Balanitaceae): Bark 5. Carissa edulis (Apocynaceae): Roots 6. Catharanthus spp. (Apocynaceae): Leaves 7. Psidium guajava (Myritaceae): Leaves 8. Coleus spp. (Lamiaceae): Leaves 9. Commiphora spp. (Burseraceae): Bark 10. Erigeron spp. (Asteraceae): Leaves 11. Fagara sp. (Rutaceae): Bark 12. Ipomoea sp. (Convovulaceae): Tubers 13. Leonotis spp. (Lamiaceae): Leaves 14. Kigeria Africana (Bignoniaceae): Bark and Fruit

128 15. Melia volkensii var. keniae (Meliaceae): Leaves and Bark 16. Mimosa pudica (Fabaceae): Leaves 17. Omocarpum trichicarpum (Fabaceae): Bark 18. Pappea capensis (Spindaceae): Bark 19. Prunus africana (Rosaceae): Bark and Leaves 20. Rhoicissus tridentate (Vitaceae): Tubers 21. Sterculia africana (Sterculiaceae): Bark 22. Striga hermonthica (Scrophuriacaee): Whole plant 23. Synadenium campactum (Euphorbiaceae): Leaves 24. Urtica massaica (Urticaceae): Leaves 25. Warburgia ugandensis (Canellaceae): Bark, Leaves and Fruit 26. Ximeria caffra (Olelaceae): Bark 27. Ajuga ramota (Hypericaceae): Leaves 28. Opuntia Sp. (Cactaceae): Fruits 29. Vernonia spp. (Asteraceae): Leaves 30. Albizia spp. (Mimosaceae): Bark 31. Euphorbia hirta (Euphorbiaceae): Whole plant 32. Rhus spp. (Anacardiaceae): Bark 33. Aspilia spp. (Asteraceae) 34. Senna spp. (Fabaceae) 35. Terminalia spp.(Compretaceae): Bark 36. Centaurea mollis (Asteraceae): Leaves

4.0 Conclusion Based on the fact that many medicinal plants are threatened in Trans-Nzoia District conservation measures should be put in place to ensure survival of this important germplasm (Kanya et al., 2004). Participatory in situ conservation of medicinal plants though a fairly new concept in Kenya should be emphasized for application by land owners as it is practical and sustainable. To achieve this objective plant nursery of selected indigenous medicinal plants enlisted in Table 2 with known uses by traditional healers should be emphasized. The seedlings then should be supplied to farmers to plant either as hedge plants or along the farm boundaries to serve as wind breakers and a source of herbs for traditional healers and pharmaceutical companies. However, other modes of in situ conservation can be explored for plants listed in Table 1.

Acknowledgements This work was supported by the U.S. A gency for International Development (Program on Biotechnology and Biodiversity Interface). The authors thank Mr. Daniel Mungai (EA) and Mr. Simon Mathenge (Department of Botany, University of Nairobi) for identifying the plants specimens.

129 References Agnew, A. D. (1994). Upland Kenya wild flowers. A flora of the ferns and herbaceous flowering plants of upland Kenya. East African Natural History Society, Nairobi. Pp. 10-112.

Beentje, H. J. (1994). Kenya Trees Shrubsand Lianas. National Museums of Kenya, Nairobi. pp. 43-627.

Grieg-Smith, P. (1983). Quantitative plant ecology. Blackwell Scientific, Oxford, P. 8-10.

Kanya, I. J. (2004). Identification and quantification of Vegetation in the proximity of Maize in Trans-Nzoia District, Kenya. M. Sc. Thesis. Jomo Kenyatta University of Agriculture and Technology, Nairobi.

Kokwaro, J. O. (1983). Medicinal plants of East Africa. Kenya Literature Bureau, Nairobi.

Ochora, J. (2004). Establishing a herbal clinic (Kenya): Sharing innovative experiences – examples of development of pharmaceutical products from medicinal plants. Third World Network of Scientists Organization 10: 119-126.

Ochora, J. (2007). Traditional herbal pharmaceuticals: where does the secret lie? Proceedings of 2007 JKUAT Scientific, technological and Industrialization conference-“Galvanizing Science and Technology for Industrialization: Towards the Millennium Development Goals”. 25th- 26th, October 2007, pp. 179-193.

Ochora, J., W. Gisesa, P. K. Njenga (2005). Does Traditional African Medicine and Practice in Kenya have a future? Proceedings of 2005 JKUAT Scientific, technological and Industrialization conference-“Leveraging Indigenous Products and Technologies through Research for Industrialization and Development”. 27th- 28th, 2005, pp. 240-246.

Riley, B. W. and Brokensha, D. (1988). The Mbeere in Kenya: Botanical Identities and Uses. Vol. II. University Press of America, Lanham.

William, J. S. (1996). Ecological census Techniques. Cambridge University Press, Cambridge.

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